Chosen Solution
I own a copy of Pokémon Gold that doesn’t boot. It gets stuck at the Game Boy screen with a scrambled Nintendo logo. I’ve re-soldered every chip on the board with flux yet nothing seems to fix it. Are one of the chips dead? Is there anything I can do? Thank you for any help :)
Sounds like dirty contact points to me. If other carts play fine, likely not the device. If that is the only cart doing this try cleaning the contacts. Use a pencil erasure to rub the contacts, length ways not cross ways, until clean and shiny. Then use either 90+% IPA or electronic contact cleaner to finish it off. If the device is the culprit, harder to clean. I use a coffee filter folded into the shape and rough thickness of contact slot, lightly covered in 90+% IPA. Insert and remove repeatedly just like you would a cart, to clean the devices cart slot contacts.
Just to make sure you didn’t miss any contacts on the chips, get the connectors with the alcohol. It works as a conductor so if something is not connected it would boot. Get it covered and test it quick before it drys. I fixed a Kirby’s Dream Land that way.
It’s dirty contact pins
